Weymoyuth Sen. Robert Hedlund is asking Attorney General Martha Coakley to use the power of her office to stop changes to the National Flood Insurance Program from going into effect this year.

The Biggert-Waters Act of 2012 will raise flood insurance rates and remove a grandfather clause that waived flood insurance for homes built before flood zone maps were created. The law takes effect at the same time the Federal Emergency Management Agency has drawn new flood zone maps that affect hundreds of properties in Marshfield and Scituate, part of Hedlund’s district.

“The new flood maps will radically increase the price of flood insurance by thousands of dollars for many homeowners and will force many others to purchase flood insurance for the first time, despite the fact that they have never experienced – and likely never will – an insurance loss due to flooding,” Hedlund wrote to Coakley.

Hedlund said the changes are “flawed and unfair,” and asked Coakley whether the state could seek an injunction to keep the law from taking effect.

In a statement, Hedlund said the new maps reflect a “doomsday type storm you only see in movies,” rather than a realistic, local analysis.

Hedlund sent the letter following a public meeting in Marshfield on Wednesday night with officials from the Federal Emergency Management Agency. In changing the flood program, agency officials said they are simply following the law passed by Congress, and there is nothing they can do.

Members of Congress who voted in support of Biggert-Waters, including Maxine Waters of California, now back a delay in its implementation, Hedlund said. The U.S. House of Representatives has already passed a one-year delay.

The U.S. Senate has yet to act, though, and FEMA therefore is going forward with its new flood maps and rates.

Hedlund also wrote to U.S. Sens. Elizabeth Warren and Edward Markey asking them to take action to delay the law.

U.S. Rep. Stephen Lynch, D-South Boston, who was at the Marshfield meeting, first suggested the possibility of an injunction, Hedlund said in the letter to Coakley.

Hedlund is turning to Coakley for assistance because the attorney general has long defended citizens from unfair insurance practices and actions of the federal government, he said.

Hedlund said the flood insurance changes are based on “irrational assumptions and flawed data,” and they warrant Coakley’s attention because of how “shockingly unfair and drastic the impact will be.”